98Z5V

The problemwon't be your ToolCraft BCG. These guys you bought the upper from ONLY deal in blem parts, ONLY. That's all they do, and they get them cheap, mark them up a little, and make money that way - that's why you got it so cheap. Question is - what's the "blem." Is it a cosmetic blem, or a functional blem?... You never, ever know, with them, until it's in your hands and you inspect it... I've warned people here about that company before. A little bit of research will show it. Always dig into any company that looks like it has prices "that are too good to be true." There's a reason. Click this link: https://forum.308ar.com/search/?q="Davidson Defense"&updated_after=any&sortby=relevancy

I stopped after your first sentence. ^^^ That thing above is literally, your first sentence... First, don't complicate shiit with complicated shiit. You did. The easiest wayto figure this all out is to buy a cheap Armalite AR-10 Rifle Receiver Extension kit, install it, and see if your gun functions. You've gone way overboard with this JP SCS and a spacer to make it fit, playing with weights, all that. Start from the basics and get a running gun, first. Once you have a running gun, go wild, and add as much complicated shiit as you want - one complicated part at a time, so you know what fails and doesn't work.

That is not a "Double Feed." A true Double Feed is only a magazine problem, forever and a day, Amen. A true Double Feed is two live rounds trying to enter the chamber at the same time - and that's the magazine's fault (either feed lips or spring pressure). Nothing else on this planet can cause a true Double Feed. Think about the name - you're double-feeding, two live rounds. The problem you have is a Failure to Eject.

We all learn from each other, man. Sometimes, the hard way...

I like those shirts...

Just add the Strike Industries LINK rails that you need, and be done...

Why not just dispense with the headache, and add a few of these? Strike Industries LINK rail sections - they developed a rail section that mounts to Key-Mod and M-LOK. I have 3 or 4 or these things, and they work. Save yourself the headache, man. https://www.strikeindustries.com/shop/products/rifle-accessories/ar-9/link-rail-section-7-slots-qd-featured-patent-pending.html

That will take alot of work, right there. I'm just sayin'...

These are the answer... Just ask @Rsquared...

You're about to get ALOT of math on that platform. It's gonna hurt, there's gonna be so much. It's gonna hurt worse for alot more people out there, though. That's the way it needed to be, though... Just wait for it...

What gets me is this thing is a gimmick - it's a solution, looking for a problem. I've heard about it for years, but I've never even looked into them before @jtallen83 posted that link, and there was an animation in there on what it does. It offers no benefit, in any way... That's my $0.02 on the thing. If the roller was on the body of the cam pin ( I thought it was) it would smooth the locking and unlocking of the bolt, into the extension, and reduce the need to "slide" in the BCG body.. This thing doesn't do anything but (possibly) roll up the left side of the receiver when the bolt is under zero pressure.

That's just a radius cut in the gas key body. This roller cam pin looks like a waste - I always thought the roller was in the stem, so it locked and unlocked a little more smoothly. That thing just rolls on the inside of the upper receiver (charging handle channel). That a crock. It only "rolls" against the upper when the bolt is fully extended - and when the bolt is fully extended, it's under no pressure. What a bunch of shiit...

Your receiver sets are made by Matrix Aerospace, and the external dimensions are identical to the Ruger SR-762 (Matrix made those, too). The Ruger has some weird things going on inside, something proprietary, and that's why I said "external dimensions..." Matrix made this receiver set with both DPMS barrel threading and Armalite AR-10 barrel threading. It looks like DB went with the DPMS-based barrel threading. Just so you know - the only thing "Armalite" or "AR-10" about the DB10s is the angled cut on the receivers - nothing else. Check this recent thread out:

There's a method to this madness - I like it. It's about to get serious, brother...

The gas keys are identical. But, please explain more about removing the gas key so you can (take out the cam pin?) remove your bolt for cleaning? I've never had to remove a gas key to take out a bolt, so I don't understand what you're talking about...

It's either 1/8" thick or 3/16" thick. Easy to measure with a tape measure. Just trying to save you some headaches, and find the right part for you. Pretty complicated, isn't it? The only thing Armalite about the receiver set you have is the cut on the upper/lower...

Looks like a good build - this will be nice.

Now, you need to determine if that receiver is DPMS high or DPMS low... https://762ar.com/dpms-a3-handguards/

Hornady put that information out, when the ELD-M came out. I don't know how they found it out, but that would be a tough job to determine... At any rate, I use Hornady ELD-M projectiles in many different calibers, and they work. They're accurate, and repeatable. I've used the older Nosler 180gr .308 "white tips," in loaded ammunition, and they work, too. I probably still have a box or two of those around here. Polymer tipped ammunition feeds just fine, and it's not even an issue. Soft-point ammo is a different story. If might feed, but catch a part of the barrel extension - and cut it. As soon as you shoot it, it might go off target - like a fletch on an arrow sticking out. I don't like soft-points through a semi-auto AR, for that reason. Some don't feed worth a shiit, and jam worse than 36gr .22LR hollowpoints in a Ruger 10/22...

Eh, mid-year changeover, or something. Now, the Matrix sets you can get are DPMS-cut.

You mean, JUST LIKE ObamaCare?... Yes, it's .gov-sanctioned extortion, brother. It only makes Pelosi, with a salary of $193.4k a year, ... - earning more than 1million a year. That's what it does.

Completely changed the operational characteristics of this rifle, thanks to Primary Arms and a $56 sale on the MagPul detachable mag system for Rem 700 Long Action Magnums. It still needs the EGW 30 MOA rail on it, but that will happen with time. For now, it's in a very good position to explore the Hornady 225gr ELD-M loads, and finalize that load. Just in time for summer in the desert. Not looking forward to that... Every bolt gun should be mag-fed. JMHO...

Or, that Microstation stuff is so complicated, that there's a trick to it, and "you have to know which way to tickle that girl" to get it to respond... Don't blame you, brother...